Dilatation catheter with angled balloon and method

Abstract

Angled balloon dilatation catheter having a flexible elongate tubular member with first and second lumens extending therethrough and with proximal and distal extremities. An angled balloon is carried by the distal extremity of the tubular member. The elongate tubular member has a tubular element extending through the balloon. The first lumen extends through the tubular element and is capable of receiving a guide wire so that the guide wire extends therethrough. The second lumen is in communication with the interior of the angled balloon for inflating and deflating the balloon. The balloon subtends a predetermined interior angle.

What is claimed is: 
     
       1. A balloon catheter comprising a flexible, elongate tubular member having at least one lumen extending therethrough and having proximal and distal extremities, an inflatable balloon which is carried by the distal extremity of the tubular member and which is preformed to subtend a predetermined interior angle between about 35° and 160° when inflated, a tubular element extending at least through the balloon interior which is preformed to subtend a predetermined interior angle between about 35° and 160° and which is adapted to receive a guide wire therethrough, and means for establshing fluid communication between a lumen in the tubular member and the interior of the balloon for inflating and deflating the balloon. 
     
     
       2. The catheter of claim 1 including a guide wire disposed in and extending through the tubular element to yieldably increase the angle subtended by the balloon. 
     
     
       3. The catheter of claim 1 including an additional elongate member extending through a lumen in the tubular member into the interior of the balloon to apply an additional yieldable force to further increase the interior angle subtended by the balloon. 
     
     
       4. The catheter of claim 3 in which said additional elongate member is a vent tube extending through a lumen in the tubular member. 
     
     
       5. The catheter of claim 1 in which the inflated balloon subtends an interior angle of about 35° to about 160°. 
     
     
       6. The catheter of claim 1 including spaced apart directional markers carried by the tubular element within the balloon, each of the markers having a different angular position with respect to the other markers. 
     
     
       7. The catheter of claim 6 in which said markers are in the form of a double helix of a radiopaque material. 
     
     
       8. The catheter of claim 1 in which the subtended angle is approximately 85°. 
     
     
       9. The catheter of claim 2 including a removable angled sleeve disposed on and frictionally engaging the exterior of the uninflated balloon to retain the predetermined angle in the balloon when inflated. 
     
     
       10. The catheter of claim 1 wherein the balloon is preformed to subtend a predetermined interior angle when inflated. 
     
     
       11. The catheter of claim 1 wherein the tubular element is preformed to subtend essentially the same interior angle as the inflated balloon. 
     
     
       12. A method for utilizing a catheter with a balloon on the distal portion thereof which is preformed to subtend a predetermined angle when inflated, a guide wire, and a vent tube, said method comprising, advancing the guide wire through the dilatation catheter to straighten the angled balloon of the catheter, inserting the guide wire into a vessel of a patient, moving the dilatation catheter over the guide wire, advancing the guide wire so that it extends through the stenosis and advancing the angled balloon over the guide wire into the stenosis, inflating the angled balloon while it is positioned in the stenosis, deflating the balloon and thereafter removing the balloon dilatation catheter and the guide wire from the vessel. 
     
     
       13. A method as in claim 12 together with the step of observing the orientation of the angled balloon after it has been inflated in the stenosis to ascertain whether it has a desired orientation in the stenosis, deflating the angled balloon if the angled balloon does not have the desired orientation in the stenosis, rotating the balloon dilatation catheter so that the angled balloon has the desired orientation in the stenosis and thereafter inflating the angled balloon in the stenosis. 
     
     
       14. A method as in claim 13 wherein the orientation of the balloon dilatation catheter is fluoroscopically detected by means of axially spaced apart markers in the balloon, each of the spaced apart markers on the balloon having a different fluoroscopically decernable angular relationship with respect to another marker. 
     
     
       15. A method of claim 14 including the step of inserting a flexible, relatively stiff element into a lumen within the catheter until it extends into the balloon and straightens the balloon so that it can be advanced into the vessel, and removing the relatively stiff element when said angled balloon has reached a position in proximity to the stenosis.